<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>头部</title>
    <link rel="stylesheet" href="../CSS/header.css">
</head>
<body>
    <!-- 头部 -->
    <header>
        <!-- 蓝色的线 -->
        <div class="header-line"></div>
    </header>
</body>
</html>